At present, Phase shifter has many applications in sensor and actuator system, and some other AC power system. So far, the electronic and photonic phase shifters have been widely used to shift the phase of an AC voltage.
The poor power management ability is the main disadvantage of those phase shifters. Ferroelectric film phase shifters based on the dielectric permittivity∈(E) control were also developed. The disadvantages of this type of phase shifter are that it has a narrow phase shift range, and demands a relatively high DC voltage and complicated fabrication process. Nobody use piezoelectric ceramic as a phase shifter before this invention.
As a result, the existing approaches do not well consider a wide phase shift range, good ability to manage high power and relatively high energy transmission efficiency.